Urban and suburban utility systems, such as septic, sewage and lighting systems, normally utilize a network vertical and horizontal tubes located beneath city and town streets Most of these may be accessed by cylindrical fixtures, normally called manholes. Additionally, it behooves public works officials and departments to have access to accurate date, including pictures, relating to location, condition and other information related to manholes. One example of important information is that it is crucial to know the dimensions and layout of each manhole in order to plan the re-lining of sewers or other renovation work.
This type of information is not always readily available or easily attainable. In many locations, the manholes were installed over many years, with several years in between, often using differing methods and often with little or no records being kept concerning their location or layout. Even today, record keeping is not at its best, sometimes non-existent.
In order to create a solution to this issue, many municipalities have decided to map their sewer systems including details related to manholes and inverts. This is a large project since each municipality can have thousands of manholes and inverts making precision and cost causes for concern. Since no specific tool or system has been developed to tackle this task, readings are inaccurate and cost is high as more expensive equipment is being used to supplement. The equipment is hard to use, often requiring more than one person. Once measurements have been taken, there is yet still room for error, as the next step requires sketching the manhole and transferring the date to an electronic database. Many times the information is so inaccurate that it cannot be relied upon and a second reading must take place wasting more time and money.